Electromyographical analysis (EMG) was performed on 9 male subjects during completion of 2 exercises (standard squat and maximum vertical jump) in 3 different cross-training shoe models. EMG electrodes were placed on the rectus femoris (quads), biceps femoris (hamstrings), tibialis anterior (shins), and gastrocnemius (calves) and muscle activity was measured during each exercise. Exercises
were divided into 3 movement phases specific to each for analysis. Shoe model was not a significant factor for either exercise based on muscle activity; however, some differences in participants subjective scores of comfort (but not stability) were found. For squats, there was a main effect of phase such that more muscle activity was produced during lowering than holding steady in the crouched position or rising. There was a main effect of muscle such that the tibialis anterior was significantly
more active than all other muscles; similarly, the rectus femoris was more active than the
biceps femoris and gastrocnemius, and the biceps femoris was more active than the gastrocnemius. For maximum vertical jump, there was a main effect of phase such that time from takeoff to landing resulted in the greatest mean and maximal muscle activation, and the lowest minimum muscle activation (explained by takeoff and flight time, respectively). There was a main effect of muscle such that the gastrocnemius produced the most activity and the rectus femoris produced the least. Additionally, knee angle dynamics, heart rate, rating of perceived exertion (squats), and time-to-completion (maximum vertical jump) did not differ by shoe model within the same exercises.